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Yuguchi, Takashi*; Ogita, Yasuhiro; Kato, Takenori*; Yokota, Rintaro*; Sasao, Eiji; Nishiyama, Tadao*
Journal of Asian Earth Sciences, 192, p.104289_1 - 104289_16, 2020/05
Times Cited Count：5 Percentile：32.38(Geosciences, Multidisciplinary)Quartz from a granitic pluton is found to have formed through sequential growth events under different mechanisms and crystallization temperatures, which can provide new insights into magmatic processes of granitic magmas that were eventually consolidified into plutons. The events were identified using (1) the description of crystal shape and occurrence, (2) the study of the internal structure with cathodoluminescence (CL), and (3) derivation of the crystallization temperatures based on TitaniQ thermometry. The magmatic quartz crystals from the Toki granite, central Japan, are characterized as having the following internal structures: oscillatory zonation, no-oscillatory zonation with luminescence graduation (gradational zonation), and heterogeneous CL. The quartz crystals with oscillatory zonation were formed in the temperature range of about 800 
C to below 700 C, which is referred to as oscillatory zoning temperature (OZT) conditions. The CL zonation pattern was controlled by the temperature conditions and titanium diffusivity in the melt (magma). The crystallization process of quartz within the Toki granite reveals the cooling processes of the granitic pluton; the lithofacies with a high frequency of oscillatory-zoned quartz underwent slower cooling under the OZT conditions than those in other lithofacies.
Chen, Z. Q.; Yamamoto, Shunya; Kawasuso, Atsuo; Xu, Y. H.; Sekiguchi, Takashi*
Applied Surface Science, 244(1-4), p.377 - 380, 2005/05
Times Cited Count：16 Percentile：55.78(Chemistry, Physical)Homo- and heteroepitaxial ZnO films were grown by pulsed laser deposition on single crystal ZnO substrate and Al
O
substrate, respectively. The surface roughness probed by atomic force microscope (AFM) depends strongly on the substrate, which is much larger for the heteroepitaxial layer. Doppler broadening of positron annihilation measurements show existence of defects in both of the films, with a higher concentration in the homoepitaxial film. Raman scattering measurements reveal the E2 phonon vibration mode at 437 cm
, which is characteristic of the wurtzite structure. These films show strong ultraviolet (UV) emission at 3.3 eV from the cathodoluminescence measurements, which indicates good optical properties.
Chen, Z. Q.; Yamamoto, Shunya; Maekawa, Masaki; Kawasuso, Atsuo; Yuan, X. L.*; Sekiguchi, Takashi*
Journal of Applied Physics, 94(8), p.4807 - 4812, 2003/10
Times Cited Count：168 Percentile：96.67(Physics, Applied)no abstracts in English
-implanted SiO
/Si studied by positron annihilation and cathodoluminescenceHirata, Koichi*; Arai, Hideyuki*; Kawasuso, Atsuo; Sekiguchi, T.*; Kobayashi, Yoshinori*; Okada, Sohei
Journal of Applied Physics, 90(1), p.237 - 242, 2001/07
Times Cited Count：4 Percentile：21.84(Physics, Applied)no abstracts in English
Murakami, Hiroaki; Kokubu, Yoko; Yokoyama, Tatsunori; Watanabe, Takahiro; Yuguchi, Takashi*; Fujikawa, Masayuki*; Nishiyama, Tadao*
no journal, ,
In order to observe micro-growth layers in carbonate, we consider availability and measurement procedure of cathodoluminescence for various carbonates. Optical-CL image and SEM-CL image provide layering structures of entire area and microscale distribution of layering structures, respectively. Thus, the approach in the order of Optical-CL measurement to SEM-CL measurement is powerful means of microscale observation of carbonate.
Ogita, Yasuhiro; Kato, Takenori*; Yuguchi, Takashi*
no journal, ,
no abstracts in English
Ogita, Yasuhiro; Yuguchi, Takashi*; Kato, Takenori*; Yokota, Rintaro*; Sasao, Eiji; Nishiyama, Tadao*
no journal, ,
no abstracts in English
Yamazaki, Hayato*; Kato, Takenori*; Ogita, Yasuhiro; Yuguchi, Takashi*
no journal, ,
no abstracts in English
Watanabe, Minori*; Kato, Takenori*; Ogita, Yasuhiro; Yuguchi, Takashi*
no journal, ,
no abstracts in English
Kato, Asuka*; Kato, Takenori*; Ogita, Yasuhiro; Yuguchi, Takashi*; Sasao, Eiji
no journal, ,
no abstracts in English
Ogita, Yasuhiro; Kato, Takenori*; Yuguchi, Takashi*
no journal, ,
no abstracts in English
